Türkiye Jeoloji Kurumu Bülteni, c. 18, 161 - 164, Ağustos 1975
Bulletin of the Geological Society of Turkey, v. 18, 161 -164, August 1975.
Description of two new Gastropod species and one sub-species from the lacustrine sediments
of Neogene age Afyon, Turkey
Afymt MHlıipmgffî^lMl^ alt tiSarwm tammt İNÂİ> MMdtwTiikkkkvw Mtasmm SmMusu, Ankara
ABSTRACT: Systematic descriptions of two newly discovered Pyrgula and Corymbina fossil species £ronı Afyon-Gürle- ydk area are given.
Samples of Pyrgula species are collected from the Lower Pliocene and Corymbina species from overlying beds.
Pyrgula species are different from the species collected from Paratethys and West Anatolian region (Denizli). Therefore two new species: Pyrgula hoyrani n.sp., Pyrgula costata n.sp. are proposed. All of the specimens of our Corymbina rhoden- sis Bukowski show slnistral features; a new sub-species, Corymbina rhodensis senestris n.ssp. is proposed.
ÖZ: Bu yazımızın konusu olan fosiller Afyon-Gürleyik (Hoyratı gölü kuzeyi) deki Neojen yaşlı sedimentlerden toplan- mıştır.
Numunelerden Pyrgula cinsine ait olanlar Pliyosen'in alt seviyesinden» Corymbina'lar ise bunların üzerindeki tabaka- lardan gelmektedir. Pyrgula'lar gerek Paratetise ve gerekse Batı Anadolu'ya (Denizli) ait türlerden ayrıcalıklar göster- mektedir, Pyrgula hoyrani n.sp., Pyrgula costata n.sp. türlerinin doğuşu bu nedene dayanmaktadır. Corymbina'lax ise hemen tümüyle senestr özellik göstermesi nedeniyle Corymbina rhodensis Bukowski'ye bağlı yeni bir alt tür yapılmıştır.
162 ÎNAL
Figure I: Location and geological map.
Sekil 1: Yer buldum ve bölge jeoloji haritası.
INTRODUCTION
Two new species of Pyrgula and sub-species of Corym- bina have been discovered in the specimens collected from Gürleyik (SE Afyon) by Aydoğan Akbulut. The brackish facies and uppermost part of Early Pliocene are indicated by Pyrgula species. The Oorymbvna species Indicate the lacus- trine facies and the lowermost part of Late Pliocene- age.
According to 1/500 000 scaled geological map of Turkey the specimens were collected from the Neogene areas (figure 1).
SYSTEMATIC STUDY
Class : Gastropoda Cuvier, 1797
Subclass : Prosobranchia Milne Edwards, 1848 Order : Mesogastropoda Thiele, 1929 Superfamily : Rissoacea Adams and Adams, 1854 Family : Truncatellidae
Subfamily : Pyrgulinae
Genera : Pyrgula Christofori and Jan, 1832
Pyrgula hoyrani n.sp.
(plate I, figure 1-2)
Derivatio-nominis
It is derived from the name of the Hoy ran, a lake from Afyon region.
Diagnose
Test small, high conical, spirally coiled; 7 whorls with protoconch, smooth first whorls; later whorls with rounded keel and thin lines of growth. Aperture is oval.
Description
Test is small, the shape is high cone and the height of the last whorl is smaller than the 1/2 of the height of the test. The number of the whorls (including protoconch) is se- ven. Protoconch and the two first whorls are smooth on the surface; in the thirth whorl appear thin lines of growth and in the fourth whorl there is rounded keel at the lower part of the suture line. The number of the keel is only one at every whorl but two at the last whorl. Aperture is oval. It is rounded at the lower part and angulated at the upper part.
It is turned-down and stuck on the last whorl at the columellar edge. It is more distinctly curved outwards at upper part where it is angulated.
Measurements of holotype: Height 6,45 mm, width 3,10 mm, angle of apex 38°.
Average measurements: Height 6,11 mm, width 2,94 mm.
Comparisons and Remarks
This species is compared with the Pyrgula species of Classic Central European Neogene (Wenz, 1942) (Jekelius, 1932 and 1944) and Denizli basins of West Anatolian (Taner, 1974). There is not resemblance of P. hoyrani with the Pyr- gula species of these basins.
Locality
Afyon-Gürleyik village.
Stratigraphical level
Upper levels of the Lower Pliocene.
Pyrgula castata n.sp.
(plate I, figure 3-4)
Diagnose
Test small with eight whorls including protoconch first whorl with smooth surface. Following whorls keeled and ribbed. Aperture rounded at the lower part and angulated at the upper part.
Description
Test is small and high conical, the height of the last whorl is 1/3 of the height of the test. 8 whorls are counted,
ÎKÎ YENÎ GASTROPOD TÜRÜ
163
including protoeoneh. The surface of protoconch and of the first whorls are smooth. Test has thin lines of growth on the following whorls. From the fourth whorl, up to the last, ap- pear under the suture line a keel noticeable ribs. These ribs start from the keel, cross the whorl and end at the end of the each whorl. The number of the nibs on one whorl is about 14-16. Aperture is rounded at the lower part and angulated at the upper part. It is turned-down and stuck on the last whorl at the columellar edge.
Measurements oif holotype: Height 5,25 mm, width 2,10 mm, angle o]f apex 38°.
Average measurements: Height 5,75 mm, width 2,22 mm.
Comparisons and Remarks
It is distinguished from P. hoyrani n.sp. by having more ribbed whorls, less noticeable keel and pseudonodose shape of the keel at the beginning of it. We cannot found similar forms when it is compared with Pyrgula ispecdes collected from European and West Anatolian basins (Denizli).
Locality
Afyon-Giirleyik village.
Stratigraphical level
Upper levels of Lower Pliocene.
Class Subclass Order Superfamily Family Subfamily Genera
Gastropoda Cuvier, 1797 Euthyneura Spengel, 1881 Basommatophora Keferstein, 1864 Lymnaeacea
Lymnaeidae Lymnaeinae
Corymbina Bukowski, 1892
Corymbina rhodensis senestris n.ssp.
(plate I, figure 5-8)
Diagnose
Medium test, with rather thick shell, short spire; four whorls including protoconch, separated last whorl from the spire. First whorls with smooth surface, the rest with ribs parallel to each other (transversal folds), sinistral aperture, with columellar edge compressed and thickened.
Description
Medium size test has thick shell. The number of the whorls including protoconch is four. Test has a short spire.
Surface df the first whorls are smooth. Thin growth lines are seen on the following whorls. On the surface starting from the third whorl up to the last, there are parallel ribs.
This ribs starting from suture lines, continue regularly towards the front forming a convex arch. The space between the ribs are equal. The last (the fourth) whorl is separated
from the spire. The suture line can be seen up to the aper- ture. Aperture is sinistral, round and slightly compressed from both sides. Outer lib (labrum) is elongated as a shovel ta the opposite side of the columellar edge. In some samples this labrum is slightly curved outwards. The inner part of the aperture is thickned and the ribs become thinner to form a winkled pattern.
Measurements of holotype: Height 17,35 mm, width 10,35
Measurements of paratype: Height 12,30 mm, width 7,40 mm.
Coinparaisons and Remarks
It resembles to Corymbina rhodensis Bukowski but it differs from it by having more shorter spire, to have the last whorl more îar away from the columellar axis and to be sinistral rather than dextral as Corymbina. rhodensis Bu- kowski (Bukowski, 1893).
Xiocality
Afyon-Giirleyik village.
StratigrrapMcal level
Lower levels of Upper Pliocene.
CONCLUSIONS
The systematic and palaeogeographic study of these fos- sils give the following results:
1) The abundance of Pyrgula species shows the charac- teristics of the facies of Ponti-Caspic, specially Dasic basins of the Paratethys. This proves that the southern border of Paratethys can be drown further southwards from the pre- sently accepted border.
2) Two new species of Pyrgula and one new sub-species of Corymbina are established.
Yayıma verildiği tarih: Nisan, 1975
REFERENCES
Bukowski, G., 1893, Die Levantinische Molluskenfauna Der Insel Rhodus: Wien, 31-38.
Jekelius, E., 1932, Die Molluskenlauna Der Dazischen Stufe Des Beckens Von Brasov: Mem. Inst. Geol. Bom&mei; Bucuregti, 81-88.
Jakelius, E., 1944, Sarmat und pont von Soceni (Banat): Mem. Inst.
Geol. Româmeı: Bucuregti, 112-164.
Taner, G., 1974, Denizli bölgesi Neojen'inin paleontolojik ve stratig- Taner, G., 1974, Denizli bölgesi Neojen'inin paleontolojik ve strati - grafik etüdü: Maden Tetkik Arama Ensütüsü Dergisi, Ankara, 83, 145-176.
Wenz, "W., 1942, Die Mollusken des Pliozans der rumanischen Erdöl - Gebiete: Senckenbergiana Wissen. Metteil. Sencken. Naturf.
Gesell. 24: Frankfurt a.M., 3-26, 49-51.
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PLATE I
